As the number of users and traffic volume continue to grow on the Internet, it becomes essential that a set of network performance metrics and measurement methodologies should be available to allow both the users and network service providers to have an accurate, common understanding of the performance and reliability of given Internet paths. Such understanding should include information on what segment of a given Internet path limits that performance and reliability. On the users' side, once equipped with a set of network performance metrics and measurement tools, it will become much easier to have an accurate knowledge of what kind of service they are getting. With this information the users will be able to compare the relative performance of the various network service providers. Similarly, knowledge from network performance measurement will also enable the network providers themselves to intelligently deploy more powerful switches to boost network capacity. Likewise, content-based service providers can use this information to optimally deploy and manage their web servers.
That is, this performance information may be used by many Internet services and systems to enable the creation of robust overlays for peer-to-peer systems or application-level multicast trees, by users to enable the selection of a server among multiple server mirrors, and by service providers to determine the placement of server replicas to improve the performance of content distribution networks. Despite many proposals on building an Internet measurement infrastructure from the research community, however, it is hard for such an infrastructure to be fully deployed and operational in the near future, due to both the scale and the complexity of the Internet.
It is increasingly the case that a given service request from a client can be fulfilled by one of several Internet servers. Examples range from short-lived interactions such as a single Web page access to a Web server, to the long-term peering relationship between two news (NNTP) servers. In all such interactions with all other things being equal, it is advantageous to access the “nearest” server with low latency or high bandwidth. Even when all other things are not equal, for instance when different Web servers have different response times, it is still useful to include the distance to each candidate host as a factor in making a selection.
There have been several research efforts on network performance measurement and analysis, the teachings and disclosures of which are incorporated in their entireties by reference thereto, including: P. Francis et al., “An Architecture for a Global Internet Host Distance Estimation Service,” Proc. of IEEE INFOCOM 1999, March 1999; Sandra G. Dykes, Clinton L. Jeffery, and Kay A. Robbins, “An Empirical Evaluation of Client Side Server Selection Algorithms,” Proc. of IEEE INFOCOM '2000, 2000; James D. Guyton and Michael F. Schwartz, “Locating Nearby Copies of Replicated Internet Servers,” Proc. of ACM SIGCOMM '95, pp. 288–298, 1995; and A. Myers, P. Dinda, and H. Zhang, “Performance Characteristics of Mirror Servers on the Internet”, Proc. of IEEE INFOCOM '99, March 1999. All these efforts have reached the common understanding that the establishment of an Internet performance measurement infrastructure is the ultimate solution for the optimal operation and healthy growth of the Internet.
One method to obtain network performance information is for each of the initiating hosts to measure the network performance itself, using either unicast or multicast tools. However, if a large number of hosts were to make independent and frequent measurements, this would have a severe impact on the Internet. Unfortunately, in current systems measurements made by one host are not made available to otherhosts. This increases the measurement overhead of such systems as each host that needs the information must independently measure it. As a result, due to both the scale and the complexity of the Internet, it is unlikely that a measurement infrastructure of such a scale will be deployed and fully operational in the near future. This problem is further exacerbated by the fact that the Internet is still growing at an exponential rate.
There exists, therefore, a need in the art for a network performance analysis architecture that is scalable to large scale networks such as the Internet, but that is not burdened by large measurement overhead.